JP2020038829A - Electrical contact for mating with mating contact - Google Patents

Abstract

To provide a contact arrangement that enables stable electrical and mechanical contact between an electrical contact and a mating contact, as well as a simple connection to an aluminum conductor.SOLUTION: An electrical contact 1 is provided for mating with a mating contact 16, including an aluminum body with a connecting portion 4 adapted to be connected to an aluminum conductor 6; a contact zone 10 disposed on a surface 8 of the aluminum body and adapted to be electrically connected to the mating contact; and at least one contact spring 12 connected to the aluminum body and having a contact region 14 for contacting the mating contact. The at least one contact spring at least partially rests on the contact zone and is formed from a material that is harder than aluminum or an aluminum alloy. The contact zone is formed from a material that is more creep-resistant than aluminum or the aluminum alloy.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrical contact for fitting with a mating contact. Furthermore, the invention relates to a contact arrangement having aluminum conductors and electrical contacts.

  In the prior art, copper contacts formed from copper or a copper alloy are used to connect electrical conductors to mating contacts. However, these copper contacts are heavy and have high material costs. However, especially in the automotive industry, it is desirable to have low weight, especially when the cross section of the conductor is large, as is partially required in electric vehicles. Accordingly, copper conductors, such as copper cables, are increasingly being replaced by aluminum conductors formed from aluminum or aluminum alloys. However, because copper is mechanically stable, copper contacts are still used to generate the required contact normal force on the mating contact. Connecting copper contacts to aluminum conductors cannot be overcome without considerable effort.

  Accordingly, the problem of the present invention is to provide a solution that allows stable electrical and mechanical contact between the electrical contact and the mating contact, as well as a simple connection to the aluminum conductor.

  According to the present invention, the problem is that an aluminum body extending along the longitudinal axis, formed from aluminum or an aluminum alloy and having a connection for connection to an aluminum conductor, and an electrical connection to a mating contact A contact zone located on the surface of the aluminum body for at least one contact spring connected to the aluminum body and having a contact area for contacting a mating contact, wherein at least one contact spring comprises The electrical contact is at least partially stationary in the zone and is formed from a material that is harder than aluminum or aluminum alloy, and the contact zone is solved by an electrical contact that is formed from a material that is more creep resistant than aluminum or aluminum alloy.

  According to the invention, a contact device comprises an electrical contact according to the invention and an aluminum conductor connected to the connection by integral joining and / or form fitting.

  The use of an aluminum body saves weight and material costs when compared to currently known electrical contacts, such as the copper contacts described above. Since the connection of the aluminum body is likewise formed of aluminum or aluminum alloy, it is possible to easily connect the aluminum conductor to the connection without the expensive treatment of the connection, for example in the case of copper contacts. is there. Contact to the mating contact is generated via at least one contact spring, so that the aluminum body is not subjected to very high mechanical stress. The current flow is absorbed by the contact zone via at least one contact spring. Due to the contact zone having higher creep resistance as compared with the aluminum body, long-term contact of the mating contact can be realized without loss of contact quality, and wear of the electrical contact can be reduced.

  In the present application, the aluminum alloy includes any alloy in which aluminum is a main component.

  The developments described below can be combined with one another independently of one another, if desired, and are each advantageous when viewed independently.

  Thus, according to a first advantageous configuration, the aluminum body can be a stamped and bent part. As a result, the aluminum body can be easily formed. Stamping and bending have proven to be particularly advantageous due to their precision and speed, especially for mass production of electrical contacts.

  The aluminum body can be formed from an aluminum / magnesium alloy, especially an AlMg3 alloy. As a result, the aluminum body can be welded with a very good inclination, so that the design of the aluminum body and / or the connection to the aluminum conductor can be further optimized. Further, such alloys have better corrosion resistance to weather conditions and salt water as compared to pure aluminum.

  According to a particularly advantageous configuration, the contact zone can be formed from a noble metal or a noble metal alloy. By using a contact zone formed from a noble metal or a noble metal alloy, surface corrosion on the contact zone, which can lead to reduced conductivity, is avoided. In particular, the contact zone can be formed from silver or a silver alloy, so that good conductivity is achieved in the contact zone and surface corrosion is avoided. The material cost of silver or silver alloys is kept to a limit when compared to other noble metals, for example gold. However, in an alternative configuration, the contact zone can also be formed from other noble metals or noble metal alloys, such as gold or gold alloys or palladium or palladium alloys. Alternatively, the contact zone can be formed from tin or a tin alloy, especially for applications in the lower temperature range, ie, below about 120 ° C.

  To avoid sharp edges at the transition between the surface and the contact zone, the contact zone can be arranged flush with the surface. In this case, coplanar arrangement means that there is no wear between the surface and the contact zone when sliding over the transition. The contact zone can be deposited on the surface by, for example, chemical vapor deposition, in particular by electron beam, or it can be galvanically deposited. Alternatively, the contact zone can be provided by a rolled cladding. In this case, the contact zone can be provided directly on the stamped strip, which is particularly advantageous for large-scale industrial production of stamped bent parts.

According to a further advantageous configuration, an intermediate layer can be arranged between the surface of the aluminum body and the contact zone. The intermediate layer can be formed, for example, from copper or a copper alloy, which can result in a saving of material in the contact zone. Thus, the intermediate layer can be formed from a material that has a lower material cost, especially as compared to the material of the contact zone. The intermediate layer, like the contact zone, can be deposited on the surface by chemical vapor deposition, in particular by electron beam, or it can be galvanically deposited. Preferably, the intermediate layer can be provided on the surface by a rolled cladding. In this case, the intermediate layer can be provided directly on the stamped strip, for example as a stripe. The intermediate layer may be provided with a contact zone, which may facilitate the mounting of the contact zone.
For this purpose, in particular, the thickness and composition of the intermediate layer can be optimized. Further, the intermediate layer can prevent creep of aluminum from the aluminum body into the contact zone.

  The material thickness of the contact zone can be from about 2 μm to about 10 μm thick. The material thickness of the intermediate layer can be from about 10 μm to about 20 μm.

  The at least one contact spring can be formed from a material such as copper or a copper alloy that is more thermally resistant than aluminum or an aluminum alloy. Alternatively, at least one contact spring can be formed from stainless steel. As a result, it is possible to ensure that the material does not soften even at a high temperature, and that the contact normal force from the contact spring to the mating contact does not decrease.

  The at least one contact spring can have a coupling region, by which the at least one contact spring is coupled to the aluminum body. Thus, the connection area can for example be gripped around the end of the aluminum body facing away from the connection, across the longitudinal axis, and can be attached to the aluminum body. Alternatively or additionally, the coupling region can be located at the free end. The coupling area can preferably have a catching mechanism, which can engage with a matching catching mechanism of the aluminum body, thus preventing the coupling area from accidentally slipping off the aluminum body I do.

  The coupling area can be in the form of a sleeve, can surround the socket cavity with the aluminum body, and the sleeve can be arranged at the free end of the aluminum body facing away from the connection.

  The at least one contact spring can be curved around the free end and project into the socket cavity.

  At least the outer surface of the sleeve facing away from the aluminum body can be coated with a noble metal. As a result, corrosion of the sleeve can be avoided. In particular, the at least one contact spring can be coated with a noble metal, at least on the contact area and / or on the support surface where the contact spring rests in the contact zone. The coating of the contact spring can in particular be made of the same material as the contact zone, so that corrosion of the contact when contacting the mating contact and / or the contact zone can be prevented.

The at least one contact spring can be curved around an end facing away from the connection. The aluminum body can in particular be at least partially configured in the form of a socket which is open longitudinally around the socket cavity, the contact zone being arranged in the socket cavity. The at least one contact spring can project into the socket cavity and can rest at least partially in the contact zone. In each case one contact zone can be arranged on both sides in the socket cavity. Alternatively, the contact zone can also extend radially around the socket cavity in the longitudinal section. The coupling area can be formed as a sleeve that can be placed on the socket.
In this case, corresponding to the side of the socket with the contact zone, at least one contact spring, preferably two contact springs, respectively, can extend away from the sleeve and bend into the socket cavity. . In this connection, the mating contact can in particular be a plug contact and / or a round contact that is contacted by electrical contacts from several sides.

  The contact spring can flex elastically between the contact zone and the contact area. When the contact spring contacts the mating contact, it can flex elastically in the direction of the contact zone, and the contact spring presses the contact zone. As a result, a stable flow of electricity is guaranteed. In this case, the contact zone can be configured to be wear-resistant, in particular against friction caused by contact springs, for example by forming the contact zone from a noble metal such as silver or a noble metal alloy such as a silver alloy. .

  According to an exemplary configuration, the aluminum body does not have any form-fitting elements, especially elastic form-fitting elements, so that contact forces are prevented from being transmitted to the aluminum body, or by the aluminum body. It is prevented from being created. This prevents the aluminum body from affecting the contact normal force, and as a result, the stability of the electrical connection between the mating contact and the electrical contact can be further improved.

  The connection can extend longitudinally on the opposite side of the socket, so that the connection is freely accessible for connection to the aluminum conductor. The connection can include a crimp sleeve that creates an arc over the connection, into which the aluminum conductor can be plugged. The crimp sleeve can then be crushed, so that the connection between the aluminum conductor and the electrical contact can be further strengthened.

  According to a particularly advantageous configuration, the aluminum conductor can be an aluminum cable that can be connected to the connection by integral joining and / or form fitting.

  The aluminum conductor can be welded to the connection, for example by ultrasonic welding or friction welding. As a result, it is possible to realize a stable integral joining connection. It has proven to be particularly advantageous if the aluminum conductor is welded to the connection by ultrasonic welding. With ultrasonic welding, the joining partner, ie the connection and the aluminum conductor, are not heated as much as compared to other welding methods. As a result, it is possible to prevent damage to materials nearby, such as the insulator of the aluminum conductor.

  Since the connection is formed from aluminum or an aluminum alloy, a welded connection between the connection and the aluminum conductor can be created without difficulty.

  Hereinafter, the present invention will be described in more detail by way of example, using an exemplary embodiment with reference to the accompanying drawings. In these figures, corresponding elements with respect to one another in design and / or function are provided with the same reference symbols.

  The combination of features shown and described in the individual exemplary embodiments is for illustrative purposes only. According to the above, features can be omitted from the exemplary embodiment if the technical impact is not significant in a particular application. Conversely, according to the above, additional features can be added in the exemplary embodiments if the technical impact is advantageous or necessary for a particular application.

1 is a schematic perspective view of an electric contact according to the present invention. 1 is a schematic sectional view of a contact device according to the present invention.

  First, the design of the electrical contact 1 according to the present invention will be described with reference to FIGS. FIG. 2 shows a contact device 3 according to the invention with an aluminum conductor 6 connected to the electrical contact 1.

  The electrical contact 1 extends along a longitudinal axis L and is formed of aluminum or an aluminum alloy and is arranged on an aluminum body 2 having a connection 4 for connection to an aluminum conductor 6 and on a surface 8 of the aluminum body 2. Contact zone 10 and at least one contact spring 12 connected to the aluminum body 2 and having a contact area 14 for contacting a mating contact 16.

  In this exemplary configuration, the aluminum body 2 is formed from an aluminum / magnesium alloy AlMg24. The aluminum body 2 is formed as a stamped and bent part 26. FIG. 1 schematically shows a stamped strip 28 as an example, with only the electrical contacts 1 shown. A plurality of electrical contacts 1 arranged side by side in a row can be arranged on the stamping strip 28, so that at least a simple and automatable mass production of the aluminum body 2 is possible.

  The aluminum body 2 has the shape of a socket 20 at the free end 18, which surrounds a socket cavity 22 for receiving a mating contact 16. The connection 4 extends from the socket cavity 22 along the longitudinal axis L away from the free end 18. At connection 4, electrical contact 1 is connected to aluminum conductor 6.

  For this purpose, the aluminum conductor 6 is applied to the surface 8 of the connection 4 by means of a welding connection 19, in particular an ultrasonic welding connection. Alternatively or additionally, the aluminum conductor 6 can be connected to the connection 4 by a crimp connection. Aluminum conductor 6 can be, for example, aluminum cable 21 formed from aluminum or an aluminum alloy. Aluminum cable 21 preferably has up to 99.7% aluminum.

  In a plane arranged transverse to the longitudinal axis L, the socket 20 has a substantially rectangular cross section, the socket 20 being open in the direction of the longitudinal axis L. In a longitudinal section 30 extending along the longitudinal axis L, two surfaces 8 facing each other are arranged, these surfaces 8 traversing the socket cavity 22 in the height direction H in the contact zone 10. punctuate. In this configuration, the contact zone 10 is formed from a noble metal 32, preferably silver 34, and is provided on the surface 8 by roll cladding.

  In order to save costs for the relatively expensive material of the contact zone 10, an intermediate layer 36 made of copper or a copper alloy is arranged between the contact zone 10 and the surface 8 in the height direction H.

  An intermediate layer 36 can likewise be provided on the surface 8 by a rolled cladding, after which the intermediate layer 36 is provided with a contact zone 10. As an alternative to the rolled cladding, both the contact zone 10 and the intermediate layer 36 can be provided by chemical vapor deposition, in particular by electron beam, or by galvanic deposition.

  The intermediate layer 36 and the contact zone 10 can preferably be provided directly on the stamped strip 28 as a stripe before bending, which is particularly advantageous for high-volume industrial production of the stamped bent part 26.

  The intermediate layer 36 allows the composition and material thickness of the intermediate layer 36 to be optimized, thereby simplifying the mounting of the contact zone 10. Further, the intermediate layer 36 can prevent creep of aluminum from the aluminum body 2 into the contact zone 10. Further, by forming the contact zone 10 from a noble metal, it is possible to prevent surface corrosion that may cause a decrease in conductivity.

  The contact zone 10 is arranged flush with the surface 8 along the longitudinal axis L, so that when slid along the longitudinal axis L, undesired wear and consequently increased wear will occur with the surface 8. Occurs at the transition between the contact zone 10.

  The contact spring 12 extends in the direction of the longitudinal axis L on the side opposite the coupling area 38. The coupling area 38 is in the form of a sleeve 40, which is arranged at the free end 18 of the aluminum body 2 facing away from the connection 4. The coupling region 38 and the aluminum body 2 may have complementary catching mechanisms, for example a catching clip, which prevent the connection between the contact spring 12 and the aluminum body 2 from being released. At the same time, it is captured in position relative to the window or notch. Particularly in vehicle applications, the electrical contacts 1 are exposed to high vibrational and / or impact stresses which can lead to a release of the connection.

  The sleeve 40 can be covered at least on its outer surface 43 facing away from the aluminum body 2 by a corrosion-resistant coating 45 made of a noble metal, for example silver. In the example shown, however, it is advantageous if both the bearing surface 47 of the contact spring 12 in which the contact spring 12 rests in the contact zone 10 and the contact area 14 are coated with a noble metal, in particular silver. The coating and the contact zone 10 are preferably formed from the same material, so that corrosion of the contacts can be prevented.

  On each side 41 of the sleeve 40 arranged in the height direction H, a pair of corrugated contact springs 12 extend away from the connection 4, curve around the free end 18 and into the socket cavity 22. Protrude. Here, the opposing contact spring 12 divides the receptacle 42 in the height direction H, and the mating contact 16 can be inserted into the receptacle 42 in the insertion direction S extending substantially parallel to the longitudinal axis. . The pair of contact springs 12 are arranged side by side in a transverse direction Q transverse to the height direction H and the longitudinal axis L and are offset from one another in the direction of the longitudinal axis L. In other words, the contact springs 12 project along the longitudinal axis L deeper into the socket cavity 22 than the contact springs 12 arranged side by side in the transverse direction.

  The contact spring 12 is formed of a material that is mechanically and thermally more resistant to relaxation than aluminum or an aluminum alloy and is stable, for example, stainless steel or copper, particularly a copper alloy, and has a corrugated shape. The curve 44 is directed toward the opposite side 41 and the second curve 46 faces away from the opposite side 41. The first curve 44 divides the receptacle 42 in the height direction H and includes a contact area 14 for contacting the mating contact 16. The contact spring 12 rests in the contact zone 10 by means of the second curve 46.

  When the mating contact 16 is plugged in, the flow of current is conducted from the mating contact 16 via the contact spring 12 to the contact zone 10 and is absorbed by this contact zone. The creep resistance of the contact zone 10 reduces wear due to creep. According to an exemplary configuration, contact zone 10 is formed from silver, thereby avoiding surface erosion that can compromise the conductivity of contact zone 10. The current flow is then guided from the contact zone 10 via the aluminum body 2 to the aluminum conductor 6. The contact normal force for contacting the mating contact 16 is generated by the contact spring 12, so that the contact normal force contacting the mating contact 16 is not generated by the aluminum body 2.

  By inserting the mating contact 16, the contact spring 12 elastically flexes between the contact area 14 and the contact zone 10 and is pressed against the contact zone 10. For this purpose, it is particularly advantageous if the contact zone 10 is formed from a mechanically strong material such as a noble metal, for example, so that the contact zone 10 can withstand the pressing force of the contact spring 12 without yielding. And is not worn by the friction between the contact springs 12 on the contact zone 10 due to the relative movement.

  The electrical contact 1 according to the invention allows a particularly simple connection between the aluminum conductor 6 and the contact 1 without any additional treatment of the contact 1 before connection. Since both components are formed from substantially the same material, it is possible to connect the aluminum conductor 6 directly to the contact 1 without risk of corrosion of the contact. For electrical contacts with large material thicknesses, especially for copper contacts, considerable difficulty has arisen in preparing the contacts for connection to aluminum conductors. In particular, galvanic coating of copper contacts with a large material thickness involves high costs. Due to the fact that the contact 1 according to the invention has an aluminum body 2 with a connection 4 for connection to an aluminum conductor 6, these difficulties can be avoided even in the case of an electrical contact 1 with a large material thickness. become.

  Furthermore, the contact according to the invention forms a cheaper and lighter alternative compared to copper contacts known from the prior art, due to the lower material cost and mass of aluminum compared to copper.

DESCRIPTION OF SYMBOLS 1 Electric contact 2 Aluminum body 3 Contact device 4 Connection part 6 Aluminum conductor 8 Surface 10 Contact zone 12 Contact spring 14 Contact area 16 Mating contact 18 Free end 19 Welding connection 20 Socket 21 Aluminum cable 22 Socket cavity 24 AlMg3
26 Stamped Bent Section 28 Stamped Strip 30 Longitudinal Section 32 Noble Metal 34 Silver 36 Intermediate Layer 38 Bonding Area 40 Sleeve 41 Height Sides 42 Receptacle 43 Outer Surface 44 First Curve 45 Corrosion Resistant Coating 46 Second Curve 47 Support surface H Height direction L Longitudinal axis S Insertion direction Q Transverse direction

Claims (14)

An electrical contact (1) for mating with a mating contact (16),
An aluminum body (2) extending along the longitudinal axis (L) and formed from aluminum or an aluminum alloy and comprising a connection (4) for connection to an aluminum conductor (6);
A contact zone (10) arranged on a surface (8) of the aluminum body (2) for electrical connection to the mating contact (16);
At least one contact spring (12) connected to said aluminum body (2) and having a contact area (14) for contacting said mating contact (16);
The at least one contact spring (12) is at least partially stationary in the contact zone (10) and is formed from a material that is harder than the aluminum or aluminum alloy, and the contact zone (10) is An electrical contact (1) formed of a material having higher creep resistance than an aluminum alloy.   The electrical contact (1) according to claim 1, wherein the aluminum body (2) is a stamped bent part (26).   The electrical contact (1) according to claim 1 or 2, wherein the aluminum body (2) is formed from an aluminum / magnesium alloy.   4. The electrical contact (1) according to claim 1, wherein the contact zone (10) is formed from a noble metal (32). 5.   5. The electrical contact (1) according to claim 1, wherein the contact zone (10) is arranged flush with the surface (8).   The electrical contact (1) according to any of the preceding claims, wherein an intermediate layer (36) is arranged between the surface (8) and the contact zone (10).   7. The device according to claim 1, wherein the at least one contact spring is elastically flexible between the contact zone and the contact area. 8. Electrical contacts (1).   The electrical contact (1) according to any of the preceding claims, wherein the aluminum body (2) has no form-fitting elements.   Electric contact (1) according to any of the preceding claims, wherein the contact zone (10) is provided in the aluminum body (2) by rolled cladding.   The at least one contact spring (12) extends opposite the sleeve (40), the sleeve (40) being form-fit connected to the free end (18) of the aluminum body (2); Electrical contact (1) according to any of the preceding claims, wherein the free end faces away from the connection (4).   The electrical contact (1) according to claim 10, wherein the at least one contact spring (12) is curved around the free end (18).   The electrical contact (1) according to claim 10 or 11, wherein at least one outer surface (43) facing away from the aluminum body (2) is coated with a noble metal.   A contact device (3) comprising an electrical contact (1) according to any one of the preceding claims and an aluminum conductor (6) connected to the connection (4) by integral joining and / or form-fitting. ).   The contact device (3) according to claim 13, wherein the aluminum conductor (6) is welded to the connection (4).

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